This invention relates primarily to power conversion systems of the inverter type and more particularly to overcurrent detection and control apparatus for controllable power inverters.
Controlled inverters have primary and secondary circuits. The primary circuit includes switching means responsive to pulsating control signals for controlling the switching or primary circuit current. Power from the primary circuit is coupled to a secondary circuit of the inverter where it is rectified and filtered to provide output voltage to an electrical load.
It is well known in the art that excessive currents in an inverter can cause irregularities in the output voltage and, if sustained, can seriously damage the inverter.
It is customary to sense the output voltage or current of the inverter and permanently shut the inverter (power supply) off if current becomes excessive. After the power supply has been shut-off it must manually be turned back on.
There are many applications for power supplies where an attendant operator is not economically practical. Further, many times, excessive inverter currents are only temporary in nature (e.g. temporary overload). In view of these temporary interruptions it is desirable to provide automatic apparatus for a power supply capable of automatic overcurrent detection, shut-off and turn on, not requiring operator intervention.